JP2005226283A - Heat exchanger and sanitary washing device equipped with it - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prolong service life of a heat exchanger. <P>SOLUTION: This heat exchanger is provided with a flow passage provided at the outer periphery of a heat generating body, a case constituting the flow passage, and a flow direction conversion means for converting direction of flow in the flow passage. Consequently, flow speed of water flowing in the flow passage is increased, surface temperature of the heat generating body is reduced, and amount of adhesion of scale deposited on the heat generating body is reduced to realize the compact and highly efficient heat exchanger having long service life. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a heat exchanger provided with a heater that heats cold water to warm water, and a sanitary washing device that cleans a local part of the human body using the heat exchanger.

  Conventionally, this type of heat exchanger has a double tube structure including a cylindrical base pipe 1 and an outer cylinder 2 as shown in FIG. A heater unit 3 is provided on a part of the outer surface of the base pipe 1. A spiral core 5 is inserted into the inner hole 4 of the base pipe 1 (see, for example, Patent Document 1).

In the above configuration, water as a fluid flows through the inner hole 4 of the base pipe 1, and at this time, the water is inserted into the inner hole 4 of the base pipe 1 and enters the screw thread 6 of the spiral core 5. The hot water is discharged through heat exchange with the heat from the heater.
JP 2001-279786 A

  However, in the conventional configuration, since the heater portion is provided outside the base pipe, an outer cylinder for enclosing and insulating the heater portion is necessary, which is a large configuration. Moreover, since the heat of the heater part escapes to the outside, there is a problem that heat exchange efficiency is poor. Furthermore, in order to insert and hold the helical core in the inner hole, it is necessary to make contact with the inner surface of the base material pipe where the heater is located, and there is a restriction that the helical core must be made of a thermally strong material. there were.

  SUMMARY OF THE INVENTION An object of the present invention is to reduce scale adhesion in a flow path and a heat generating part by providing a flow direction conversion means in a small heat exchanger having high heat exchange efficiency and a sanitary washing apparatus using the heat exchanger.

  In order to solve the conventional problems, a heat exchanger according to the present invention and a sanitary washing device using the heat exchanger include a flow path provided on an outer periphery of a heating element, a case constituting the flow path, and the flow path. A flow direction conversion means for converting the flow direction is provided.

  Accordingly, since the heat insulation is performed by the flow path by providing the flow path on the outer periphery of the heating element, it is not necessary to provide a thermal insulating layer, and the size can be reduced. And it can be set as the structure which does not escape heat outside by enclosing a heat-emitting part with a flow path, and can improve heat exchange efficiency.

  In addition, since the flow direction changing means provided in the flow path can be held by the inner wall of the case at a low temperature, it can be used even with a material having low heat resistance such as resin, so that it is excellent in workability and lightweight. it can.

  Then, the flow rate can be increased by changing the direction of the water flowing in the flow path to a direction that reduces the apparent flow cross-sectional area by the flow direction conversion means. When the flow rate is increased, the boundary layer between water and the heating element is narrowed, so that an increase in the surface temperature of the heating element can be prevented, and adhesion of scales and the like generated on the surface of the heating part can be reduced.

  In addition, by disturbing the flow of water flowing in the flow path by the flow direction conversion means, the water flow is turbulent, the boundary layer between water and the heating element is narrowed, and the heating element surface temperature is prevented from rising, thereby generating heat. It is also possible to reduce adhesion of scale and the like generated on the surface of the part.

  Furthermore, since the flow rate is fast, it can be discharged together with running water outside the heat exchanger without depositing scale.

  The heat exchanger of the present invention and the sanitary washing apparatus equipped with the heat exchanger increase the flow velocity of the water flowing in the flow path by installing flow direction conversion means in the flow path provided on the outer periphery of the heating element, Adhesion of scales and the like generated in the flow path can be reduced, and it is possible to achieve small size, high efficiency, and long life.

  According to a first aspect of the present invention, there is provided a flow path cross-sectional area by providing a flow path provided on the outer periphery of the heating element, a case constituting the flow path, and a flow direction conversion means for converting the flow direction in the flow path. By reducing the flow rate, the flow rate of water flowing in the flow path can be increased, and the deposits such as the scale of the heat generating part and the flow path can be reduced. can do.

  In the second invention, in particular, the flow direction changing means according to the first invention is provided at least upstream or part of the downstream of the flow path, so that the flow path can be The pressure loss can be reduced, and the weight and cost can be reduced.

  In the third aspect of the invention, in particular, the flow direction changing means of the first or second aspect of the invention is intermittently provided in the flow path, so that the pressure loss of the flow path can be reduced as compared with continuous provision. it can.

  In the fourth aspect of the invention, in particular, the flow direction changing means of the first to third aspects of the invention is provided in a region where the surface temperature of the heating element is equal to or higher than a predetermined temperature, so that the temperature of the heating element is increased. Since the flow velocity can be increased, the temperature of the heating element can be effectively prevented from rising excessively, and the amount of scale adhesion can be reduced.

  In the fifth aspect of the invention, in particular, the flow direction changing means of the first to fourth aspects of the invention is configured to be provided in a region where the surface temperature of the heating element is equal to or higher than a predetermined temperature, in the vicinity thereof and upstream, so that the heating element has a high temperature As a result, the flow rate in the region where the temperature of the heating element becomes high can be increased, so that the temperature of the heating element can be prevented from rising excessively, and the scale adheres. The amount can be reduced.

  In the sixth aspect of the invention, in particular, by providing a gap between the flow direction conversion means and the case of the first to fifth aspects of the invention, heat from the heating element is transferred to the case via the flow direction conversion means. This makes it difficult to cause thermal damage to the case.

  In the seventh aspect of the invention, in particular, by providing a gap between the flow direction conversion means of the first to fifth aspects of the invention and the heating element, the flow direction conversion means does not directly contact the heating element, so that the heat flows in the flow direction. It becomes difficult for heat to be transferred to the conversion means, preventing thermal damage to the flow direction conversion means and extending the life.

  In the eighth aspect of the invention, in particular, the flow direction conversion means of the first to seventh aspects of the present invention is configured to convert the flow direction in the swirl direction, whereby the direction of water flowing in the flow path without significantly increasing the pressure loss. Can be changed.

  In the ninth aspect of the invention, in particular, the flow direction changing means of the first to eighth aspects of the present invention is constituted by a guide provided at least in a part of the flow path, so that the water flowing in the flow path with a simple structure is provided. Since the direction can be changed, space can be saved.

  In the tenth aspect of the invention, in particular, the flow direction changing means of the first to ninth aspects of the present invention is integrally provided on the inner wall of the case, so that the water flowing through the flow path follows the inner wall of the case by centrifugal force. The flow direction converted to the end can be maintained.

  In the eleventh aspect of the invention, in particular, the flow direction changing means of the first to ninth aspects of the invention is configured to be integrally provided on the surface of the heating element, thereby increasing the surface area of the heating element and improving heat dissipation, An increase in the surface temperature of the heating element is suppressed, adhesion of scales and the like generated on the surface of the heating element can be prevented, high efficiency can be realized, and a long life can be achieved.

  In the twelfth aspect of the invention, in particular, the flow direction conversion means of the first to ninth aspects of the present invention is configured as a separate member from the case and the heating element, so that the flow direction conversion means is completely fixed to the case or the heating element. Instead, the scale can be peeled off by a physical force by holding it in a movable state by a flow force received from the flow.

  In the thirteenth aspect of the invention, in particular, the flow direction conversion means of the eighth aspect of the invention has a configuration in which the inflow port is eccentrically provided, whereby the flow of water in the flow path can be smoothly guided in the turning direction. .

  In the fourteenth aspect of the invention, in particular, the flow direction changing means of the eighth or thirteenth aspect of the present invention is configured by providing the outlet in an eccentric manner, whereby the flow of water in the flow path can be guided in the swirling direction. .

  A fifteenth aspect of the present invention is a sanitary washing apparatus provided with the heat exchanger according to the first to fourteenth aspects of the invention. By downsizing the heat exchanger, the sanitary washing apparatus main body can be downsized, and a narrow toilet It can be easily installed in a space, and by preventing the scale from adhering at an early stage, it is possible to prevent clogging of scale debris into the cleaning nozzle of the sanitary cleaning device, and it has a long service life and is unlikely to cause malfunctions. It can be a device.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. Note that the present invention is not limited to the present embodiment.

(Embodiment 1)
FIG. 1 shows a cross-sectional view of a heat exchanger according to the first embodiment of the present invention.

  In FIG. 1, the heat exchanger includes a sheathed heater 7 as a heating element that heats water as a fluid, a case 9 that surrounds the outer periphery of the sheathed heater 7 to form a flow path 8, and water in the flow path 8. It comprises a spring 10 as a flow direction changing means for inducing a flow in the turning direction. And the inflow port 11, the outflow port 12, the electrode terminals 13 and 14 of a sheathed heater, and the O-ring 15 for sealing a flow path are provided. In addition, 16 arrows in the figure indicate the flow of water.

  About the heat exchanger comprised as mentioned above, the operation | movement and an effect | action are demonstrated below.

  First, as shown in FIG. 2, the sheathed heater 7 as a heating element has a heating wire 18 arranged in a coil shape in a copper pipe 17 in which magnesium oxide (not shown) is sealed. . Then, by supplying electricity to the electrode terminals 13 and 14 connected to the heating wire 18, the heating wire 18 is heated, and heat is transmitted to the copper pipe 17 through the magnesium oxide, so that the outer periphery of the copper pipe 17 is The flowing water is heated to become warm water and heat exchange is performed.

  At this time, as shown in FIG. 3, water enters the inlet 11 provided at the side surface position eccentric from the center of the case 9, flows into the outer periphery of the copper pipe 17, and further along the outer periphery of the copper pipe 17. The spirally arranged spring 10 swirls around the outer periphery of the copper pipe 17 as indicated by an arrow 16 and is discharged again from the discharge port 12 provided at the side surface position eccentric from the center of the case 9. .

Here, the springs 10 arranged in a spiral form have a flow path cross-sectional area constituted by a pitch between the springs 10, which is an apparent flow path cross-sectional area, and a gap between the sheathed heater 7 and the case 9. It was made to turn in the direction and pitch which become narrower than the cross-sectional area of the doughnut-shaped flow path comprised between the pipes 17. As a result, the flow velocity of the swirling flow 16 that flows spirally along the spring 10 becomes faster than when the spring 10 is not provided. For example, when the outer diameter of the sheathed heater 7 is φ6.5 mm, the inner diameter of the case 9 is φ9 mm, and the pitch of the springs 10 is 6 mm, the channel cross-sectional area without the springs 10 is about 30 mm ² , Since the apparent channel cross-sectional area when using the spring 10 is about 7.5 mm ² , the flow rate can be increased about four times when the same flow rate is applied. Further, by making the water flow 16 swirl, the pressure loss does not increase relatively even if the flow path cross-sectional area is reduced. Furthermore, by providing the inflow port 11 and the outflow port 12 at the side surface position eccentric from the center of the case 9, the water flow 16 in the flow path 8 can be smoothly guided in the turning direction, thereby reducing pressure loss. can do.

  Further, when the distance through which the fluid flows becomes long, the rectifying effect is gradually activated, and the turning force is weakened to flow along the sheathed heater 7. In that case, since the cross-sectional area of the flow path becomes wide, the flow velocity decreases. However, in the present invention, since the swirl flow is sustained to the outlet 12 by the spring 10, a high flow rate can be maintained, so the boundary between the copper pipe 17 in the flow path 8 and the water that is the fluid is formed. The area becomes very narrow over the whole area. A flow velocity distribution diagram showing this state is schematically shown in FIGS. As shown in FIG. 4, when the flow velocity is low, the boundary layer 19 becomes wide. However, when the flow velocity is high and the water flow becomes turbulent, the flow becomes narrow like the boundary layer 20 of the flow velocity distribution shown in FIG. The surface temperature of the pipe 17 does not rise excessively. In general, since the amount of precipitation of the scale component increases as the temperature increases, the flow rate of the water flowing in the flow path 8 is increased as in the present embodiment, and the boundary layer region between the copper pipe 17 and the water is narrowed. Thus, it is possible to suppress an increase in the surface temperature of the copper pipe 17, and as a result, the amount of scale attached to the copper pipe 17 can be reduced. In this embodiment, in order to increase the scale amount reduction effect, the flow velocity is increased until the turbulent flow is obtained by the spring 10 which is the flow direction conversion means. Since the region of the boundary layer between the copper pipe 17 and the water can be narrowed by increasing the flow velocity by a certain spring 10, a scale reduction effect can be obtained.

  Furthermore, even when the scale is deposited on the copper pipe 17, the flow rate of the water flowing in the flow path 8 is high, so that the deposited scale has an effect of flowing downstream, and the scale is crushed small and flows downstream. As it goes, there is no clogging downstream. And since a scale becomes difficult to adhere in a heat exchanger, the lifetime as a heat exchanger can be extended. Moreover, by making it a smooth flow of a spiral, it is possible to reduce pressure loss of the flow path 8 while having a high flow rate, and to improve the heat exchange efficiency by narrowing the boundary layer between the copper pipe 17 and water. And miniaturization can be realized.

  Thus, the flow path 8 is constituted by the case 9 provided on the outer periphery of the sheathed heater 7 which is a heating element, and the flow path 8 is provided with the spring 10 as the flow path converting means. The flow rate of water flowing through the inside of the pipe 8 can be increased, and deposits such as scales generated on the surface of the copper pipe 17 can be peeled off or pulverized. Further, the flow velocity is increased and the interface between the copper pipe 17 and the water is narrowed, so that a small size and high efficiency can be realized, and the scale adhesion can be reduced and the life can be extended. In addition, by increasing the flow rate, the generation of bubbles can be reduced, the generation of scale can be suppressed, and the temperature of the surface of the copper pipe 17 can be suppressed low, so the generation of boiling noise can be reduced. And since the heat insulation is performed by the flow path 8 by providing the flow path 8 in the outer periphery of the sheathed heater 7 which is a heat generating body, it is not necessary to provide a thermal insulation layer, and it can be reduced in size. Moreover, it can be set as the structure which does not escape heat outside by enclosing the heat generating part with the flow path 8, and can improve heat exchange efficiency.

  Further, the spring 10 as the flow direction conversion means is configured using a member different from the sheathed heater 7 and the case 9 as the heating elements, so that the spring 10 is not completely fixed to the sheathed heater 7 or the case 9. Since a part of the spring 10 is held in a freely slidable state, it vibrates due to the flow force and spring force received from the flow, so that the effect of peeling off the scale can be obtained.

  Furthermore, when using it in an area where the scale component of tap water is small or in an area where tap water pressure is low, the spring 10 of another member is removed so that the pressure loss is reduced so as to reduce the low pressure loss. It is possible to prevent the scale from adhering by increasing the flow rate and reducing the low pressure loss by changing the position or by attaching the mounting location to a location where the flow velocity becomes slow. Moreover, since the replacement at the time of abnormality is facilitated, the maintainability can be improved.

  In addition, since the spring 10 is configured to have a gap with the sheathed heater 7 that is a heating element, the spring 10 is not in direct contact with the sheathed heater 7, so that heat is not easily transferred to the spring 10, Thermal damage to the spring 10 can be prevented, and the life can be extended. Furthermore, since it becomes difficult for heat to be transferred to the spring 10, even a material having low heat resistance such as resin can be used. Therefore, the spring 10 can be manufactured from a material that is easy to process, and can be light. Note that it is not necessary to provide a gap between the spring 10 and the sheathed heater 7 in the entire range. For example, there is no problem even if the spring 10 and the sheathed heater 7 are partially in contact with each other. However, in that case, it is desirable to make the spring 10 non-metallic, or to make the same metal as the sheath material of the sheathed heater 7 in order to prevent corrosion.

  Further, since the spring 10 is configured to have a gap with the inner wall of the case 9, heat from the sheathed heater 7 is not easily transferred to the case 9 via the spring 10, so that the case 9 is thermally damaged. Is less likely to occur and the life can be extended. Furthermore, since the water tends to flow along the inner wall of the case 9 due to centrifugal force, the peeled scale flows along the inner wall of the case 9 and can be prevented from being caught on the spring 10 and being deposited on the surface of the copper pipe 17 again. It can be a lifetime. Note that it is not necessary to provide a gap between the spring 10 and the inner wall of the case 9 in the entire range. For example, there is no problem even if the spring 10 and the inner wall of the case 9 are in contact with each other.

  Furthermore, the assembly of the spring 10 can be improved by providing a gap with both the sheathed heater 7 and the inner wall of the case 9.

  In addition, although the material of the sheath of the sheathed heater 7 was demonstrated with the copper pipe, other metal pipes, such as a SUS pipe, have the same effect. The flow direction changing means has been described as a spring, but the same applies to a metal spring, a spiral wire having no spring property, or a resin equivalent shape. Further, when used in a sanitary washing apparatus, the flow rate is about 100 to 2000 mL / min. Therefore, the outer diameter of the copper pipe 17 is about φ3 to 20 mm, and the spiral pitch is preferably about 3 to 20 mm. The inner diameter of the case 9 can be set in a range of φ5 to 30 mm so that the flow velocity is increased. Further, when a spring is used as the flow direction changing means, the spring has a wire diameter of about 0.1 to 3 mm and excellent workability. Although the pitch has been described as being constant, it is also possible to make the pitch partially narrower, wider, or gradually changed.

  In the present embodiment, the spring 10 has been described as the flow direction changing means. However, even if the flow rate is increased by using a blade other than the spring for converting the flow, the effect of preventing the adhesion of the scale can be obtained.

  Further, in this embodiment, the scale adhesion amount is reduced by increasing the flow velocity. However, the flow of water is turbulent by disturbing the flow of water flowing in the flow path by the flow direction changing means. Even in the configuration, since the region of the boundary layer between the copper pipe 17 and water can be narrowed, a scale reduction effect can be obtained.

(Embodiment 2)
FIG. 6 is a sectional view of a heat exchanger according to the second embodiment of the present invention. The difference from FIG. 1 shown in the first embodiment is that a guide 23 which is a flow direction changing means for forming a flow path 22 in a spiral shape is provided on the inner wall of the case 21 so as to be integrated with the case 21. Is a point. Others are the same as those of the first embodiment shown in FIG. 1, and the detailed description is omitted with the same numbers hidden.

  About the heat exchanger comprised as mentioned above, the operation | movement and an effect | action are demonstrated below.

  By adopting a configuration in which the guide 23 is provided on the inner wall of the case 21, the water flowing through the flow path 22 flows along the inner wall of the case 21 by centrifugal force, so that the turning force is provided by the guide 23 provided on the inner wall of the case 22. Can be kept effective. Further, since the flow direction changing means is realized by the guide 23, the flow direction can be converted with a simple configuration, so that space can be saved. Further, the case 21 and the guide 23 are integrally formed, so that the assemblability is improved.

  Thus, the flow velocity of the water flowing through the flow path 22 can be increased by effectively maintaining the turning force. Therefore, as in the first embodiment, the interface between the copper pipe 17 and the water is narrowed, so that it is possible to achieve an effect such as a small size and high efficiency and a reduction in scale adhesion and a long life. Can do.

  In addition, since the guide 23 is provided with a gap Ha between the sheathed heater 7 which is a heating element, the guide 23 is not in direct contact with the sheathed heater 7, so that heat is not easily transferred to the guide 23. The thermal damage of the guide 23 can be prevented and the life can be extended. The guide 23 does not need to be provided with a gap between the sheathed heater 7 in the entire range. For example, there is no problem even if the guide 23 and the sheathed heater 7 are partially in contact with each other.

  Furthermore, although the guide 23 is shown as an example integrated with the case 21, there is no problem even if the guide 23 is bonded to the case 21.

  In this embodiment, the guide 23 is described as the flow direction changing means. However, an effect of preventing the adhesion of scale can be obtained even with a blade other than the guide for converting the flow.

(Embodiment 3)
FIG. 7 is a cross-sectional view of a heat exchanger according to the third embodiment of the present invention. The difference from FIG. 1 shown in the first embodiment is that a guide 33 as flow direction changing means for forming a flow path 32 in a spiral shape on the surface of a sheathed heater 31 as a heating element is integrated with the sheathed heater 31. It is a point prepared to become. Others are the same as those of the first embodiment shown in FIG. 1, and the detailed description is omitted with the same numbers hidden.

  About the heat exchanger comprised as mentioned above, the operation | movement and an effect | action are demonstrated below.

  By providing the guide 33 on the surface of the sheathed heater 31 as a heating element, the surface area of the sheathed heater 31 is increased, the heat dissipation is improved, the increase in the surface temperature of the sheathed heater 31 is suppressed, and the surface of the sheathed heater 31 is suppressed. It is possible to prevent the generated scale from adhering. Furthermore, since the surface area of the sheathed heater 31 is increased, the watt density on the surface of the sheathed heater 31 is also reduced, so that high efficiency can be realized and a long life can be achieved. Further, since the flow direction changing means is realized by the guide 33, the flow direction can be converted with a simple configuration, so that space can be saved. Furthermore, assemblability improves by comprising the sheathed heater 31 and the guide 33 integrally. The same effect can be obtained even if the guide 33 is bonded to the sheathed heater 31 or brazed.

  In addition, since the gap Hb is provided between the inner wall of the case 9 and the heat from the sheathed heater 31 is not easily transferred to the case 9 via the guide 33, the case is less likely to be thermally damaged. It can be a long life. Further, since the spirally flowing water tends to flow along the inner wall of the case 9 due to centrifugal force, the peeled scale flows along the inner wall of the case 9 and is caught by the guide 33 and is deposited on the surface of the sheathed heater 31 again. Can be prevented, and can have a long life.

  In this embodiment, the guide 23 is described as the flow direction changing means. However, an effect of preventing the adhesion of scale can be obtained even with a blade other than the guide for converting the flow.

(Embodiment 4)
FIG. 8 is a cross-sectional view of a heat exchanger according to the fourth embodiment of the present invention. The difference from FIG. 1 shown in the first embodiment is that a spring 41 as a flow direction changing means is provided in a part on the downstream side, and a spring support base that supports the spring 41 so as not to fall downward. 42 is provided. Others are the same as those of the first embodiment shown in FIG. 1, and the detailed description is omitted with the same numbers hidden.

  About the heat exchanger comprised as mentioned above, the operation | movement and an effect | action are demonstrated below.

  As shown in FIG. 3, the inflow port 11 is attached in a direction eccentric from the side surface of the case 9. Therefore, as shown in FIG. 6, even if there is no spring, the water that has entered the water flows while swirling along the cylindrical flow path 43 formed by the case 9 and the copper pipe 17, and the state is maintained. Become. However, when it is in the vicinity of an intermediate point between the inlet 11 and the outlet 12, the momentum of turning declines. If the cylindrical flow path continues as it is, the swirl component disappears and the flow is in the axial direction. When the flow is in the axial direction, the cross-sectional area of the flow path becomes larger, and the boundary layer between the copper pipe 17 and water becomes wider due to a decrease in the flow velocity. As a result, the surface temperature of the sheathed heater 7 increases and the scale adheres. The amount will increase. Therefore, by installing the spring 41 as the flow direction changing means in the vicinity of the turning where the turning begins to decline, that is, in the region downstream of the central portion where the flow velocity becomes slow, the turning flow path 44 is formed and swirled. Can be returned to. As a result, the flow rate is increased and the amount of scale adhesion can be reduced.

  Further, on the upstream side, compared with the downstream side, since the spring 41 is not provided, the flow passage cross-sectional area is widened, so that the flow velocity is slow. However, since a spring is contained in the downstream side, the apparent flow path cross-sectional area is narrow, and the flow velocity is faster than that on the upstream side. In this way, the scale can be prevented from adhering to the downstream side by making the flow velocity faster than the upstream side. In particular, since the temperature of the water is higher on the downstream side due to the heat exchange of the water, and the surface temperature of the copper pipe becomes higher together with the water, the generation of scale increases. However, the scale 41 can be prevented from being attached by disposing the spring 41 as the flow direction changing means on the downstream side.

  And since the spring 41 is arrange | positioned only to the half area | region of the whole flow path, pressure loss can be decreased rather than arrange | positioning a spring in the whole region.

  In addition, although it demonstrated by providing the spring 41 which is a flow direction conversion means in the downstream part from the center, you may start from the upstream from the center, and if it is set as the structure moved according to the adhesion state of a scale, it can respond. . At this time, it is possible to cope with the movement of the spring 41 by providing a plurality of spring support bases 42 or making them slidable. In addition, since the spring 41 is not in the entire flow path, the pitch of the spring 41 can be freely changed. In the case of tap water with a small scale component, the pitch can be widened to obtain a low pressure loss. it can. For example, since the sheathed heater 7 is simply sandwiched between the O-rings 15, it can be easily removed, and the pitch can be easily changed by removing the spring 41.

  Furthermore, as shown in FIG. 9, by disposing the springs 45, 46, 47 as the flow direction changing means intermittently, the turning force can be reapplied and the flow velocity can be increased. In a sheathed heater using a long pipe, if a spring is arranged in the entire area, the pressure loss increases. Therefore, intermittently arranging a spring as shown in FIG. 9 can reduce the low pressure loss and increase the flow velocity. Can prevent the adhesion of scale.

  Even in the wakes 50 and 51 of the spring channels 48 and 49 that are intermittently arranged, the swirling flow continues for a while, so that even if there is a spring-free channel region, it can be a swirling flow. Then, when the turning is weakened, the spring is arranged to generate the turning component again, thereby increasing the flow velocity.

  By disposing the flow direction changing means intermittently in this way, it can be applied to a long heat exchanger, and a long-life heat exchanger with low pressure loss and little scale adhesion can be realized. In particular, when there is a bend like a U-shape, the U-shaped portion can be configured as a flow path without a spring, and a spring can be arranged in a straight portion, and a compact heat exchanger can be obtained.

  In this embodiment, the springs 41, 45, 46, 47 are used as the flow direction changing means, but it may be configured integrally with the case 9 and the sheathed heater 7.

(Embodiment 5)
FIG. 10 is a cross-sectional view of a heat exchanger according to a fifth embodiment of the present invention. The difference from FIG. 1 shown in the first embodiment is that a spring 61 as a flow direction changing means is provided in a region where the surface temperature of the copper pipe 17 is equal to or higher than a predetermined temperature, and the spring 61 falls downward. This is the point that a spring support base 42 is provided so as to support it. Others are the same as those of the first embodiment shown in FIG. 1, and the detailed description is omitted with the same numbers hidden.

  About the heat exchanger comprised as mentioned above, the operation | movement and an effect | action are demonstrated below.

  As shown in FIG. 2, the sheathed heater 7 heats water by heating the coiled heating wire 18, but the temperature of the central portion is the highest due to thermal interference between the heating wires 18. have. In addition, the temperature of the water is higher on the downstream side due to heat exchange of the water, and the surface temperature of the copper pipe 17 increases with the water. For these reasons, the surface temperature of the copper pipe 17 rises in the part of the region A shown in FIG. 10, that is, in the region centered slightly downstream from the center of the sheathed heater 7, and as a result, the region A This will increase the amount of scale attached.

  Therefore, in this embodiment, the spring 61 as the flow direction changing means is provided in the region A where the surface temperature of the copper pipe 17 is equal to or higher than the predetermined temperature. As a result, the flow rate of water in the region A can be increased, so that the surface temperature of the copper pipe 17 can be prevented from increasing and the amount of scale adhesion can be reduced. The predetermined temperature is desirably 60 ° C., more preferably 45 ° C. This is because when the temperature of the water containing scale exceeds about 60 ° C., the amount of scale adhesion tends to increase rapidly.

  Moreover, since the spring 61 is arrange | positioned only in the one part area | region of a flow path, pressure loss can be decreased rather than arrange | positioning a spring in the whole region.

  Furthermore, as shown in FIG. 11, by providing a spring 62 as a flow direction conversion means in the vicinity and upstream of the region A where the surface temperature of the copper pipe 17 is equal to or higher than a predetermined temperature, the spring 62 is made of a material that is weak against heat. However, since the surface temperature of the copper pipe 17 is provided at a low position, there is no failure due to heat. Further, since the swirling flow imparted by the spring 62 lasts for a while, the region A without the spring 62 can also be swirling flow. Even in this case, since the spring 62 is disposed only in a partial region of the flow path, the pressure loss can be reduced as compared with the case where the spring is disposed in the entire region.

  In the present embodiment, the springs 61 and 62 are used as the flow direction changing means. However, the springs 61 and 62 may be integrated with the case 9 and the sheathed heater 7.

(Embodiment 6)
FIG. 12 is a sectional view showing a sanitary washing device according to a sixth embodiment of the present invention. And it is the structure of the sanitary washing apparatus using the heat exchanger in any one of Embodiment 1-5, and the heating toilet seat 72 and the sanitary washing apparatus main body 73 are installed on the toilet bowl 71. FIG. And the heat exchanger 74 is provided in the sanitary washing apparatus main body 73, and the heat-exchanged hot water is ejected from the washing nozzle 75 to wash the local part of the human body 76. The sanitary washing device main body includes a shut-off valve 77 and a flow rate control device 78 as main components. Other parts such as the control board are omitted.

  In such a sanitary washing device, the heat exchanger 74 that is small and has little scale adherence is incorporated in the sanitary washing device main body 73, so that the size of the main body is reduced and the life of the heat exchanger is extended and the sanitary washing is performed. The life of the apparatus can be extended, and the hygienic washing apparatus with stable operation can be obtained without clogging not only the heat exchanger 74 but also the washing nozzle 75 and the like.

  In particular, by using a cylindrical small heat exchanger, the heat exchanger 74 can be installed in the lower part of the cleaning nozzle 75 that has become a dead space due to the installation of the expanding and contracting cleaning nozzle 75. Can contribute to

  In addition, since the scale is difficult to adhere to the heat exchanger, the outflow of the scale is also suppressed, so that the scale is not clogged with the cleaning nozzle 75, the flow rate control device 78, etc., and the effect that it can be used for a long time with stable operation is obtained. is there.

  As described above, the heat exchanger according to the present invention and the sanitary washing device using the heat exchanger include flow direction conversion means for converting the flow direction in the flow path provided on the outer periphery of the heating element, so that the water flowing through the flow path is provided. By increasing the flow velocity, the boundary layer between the heating element and water can be narrowed and the surface temperature of the heating element can be lowered, so that the amount of adhesion of scales and the like can be reduced. As a result, it is possible to obtain a heat exchanger that is small, has high efficiency, and has a long life. And the sanitary washing device using it can realize downsizing of the sanitary washing device body by downsizing the heat exchanger, can be easily installed in a narrow toilet space, has a long life, and It can be set as the apparatus which a malfunction does not generate | occur | produce easily.

Sectional drawing of the heat exchanger in Embodiment 1 of this invention Cross section of the heat exchanger Cross section of the heat exchanger Flow distribution diagram in heat exchanger Flow distribution diagram in heat exchanger Sectional drawing of the heat exchanger in Embodiment 2 of this invention Sectional drawing of the heat exchanger in Embodiment 3 of this invention Sectional drawing of the heat exchanger in Embodiment 4 of this invention Sectional drawing of the heat exchanger which shows the other Example of the same heat exchanger Sectional drawing of the heat exchanger in Embodiment 5 of this invention Sectional drawing of the heat exchanger which shows the other Example of the same heat exchanger Sectional drawing of the sanitary washing apparatus in Embodiment 6 of this invention Cross-sectional view of a conventional sanitary washing device

Explanation of symbols

7 Sheathed heater (heating element)
8 Flow path 9 Case 10 Spring (flow direction changing means)
23 Guide (flow direction changing means)
73 Sanitary washing device 74 Heat exchanger

Claims (15)

A heat exchanger comprising a flow path provided on an outer periphery of a heating element, a case constituting the flow path, and flow direction conversion means for converting a flow direction to the flow path. The heat exchanger according to claim 1, wherein the flow direction conversion means is provided at least at a part of the upstream or downstream of the flow path. The heat exchanger according to claim 1 or 2, wherein the flow direction conversion means is provided intermittently in the flow path. The heat exchanger according to any one of claims 1 to 3, wherein the flow direction conversion means is provided in a region where the surface temperature of the heating element is equal to or higher than a predetermined temperature. The heat exchanger according to any one of claims 1 to 4, wherein the flow direction conversion means is provided in a region where the surface temperature of the heating element is equal to or higher than a predetermined temperature, and in the vicinity and upstream thereof. The heat exchanger according to any one of claims 1 to 5, wherein a gap is provided between the flow direction conversion means and the case. The heat exchanger according to any one of claims 1 to 5, wherein a gap is provided between the flow direction conversion means and the heating element. The heat exchanger according to any one of claims 1 to 7, wherein the flow direction conversion means converts the flow direction to a turning direction. The heat exchanger according to any one of claims 1 to 8, wherein the flow direction conversion means includes a guide provided at least in a part of the flow path. The heat exchanger according to any one of claims 1 to 9, wherein the flow direction conversion means is integrally provided on the inner wall of the case. The heat exchanger according to any one of claims 1 to 9, wherein the flow direction conversion means is integrally provided on a surface of the heating element. The heat exchanger according to any one of claims 1 to 9, wherein the flow direction conversion means is provided as a separate member from the case and the heating element. The heat exchanger according to claim 8, wherein the flow direction conversion means is provided with an eccentric inlet. The heat exchanger according to claim 8 or 13, wherein the flow direction converting means is provided with an eccentric outlet. A sanitary washing apparatus comprising the heat exchanger according to claim 1.

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